1. Field of the Invention
The present invention relates to a position measuring system having a scale which can be arranged with the aid of a groove provided on a profiled element or guide profile.
2. Discussion of Related Art
Position measuring systems of this type are employed in many areas, for example in connection with measuring apparatus, machine tools, metal-working machines, laser installations, positioning installations, wood-working machines, automatic hard-facing machines, handling installations, welding installations, eroding installations, presses, hoists, elevators, and the like.
Moreover, areas of employment for such measuring systems lie in the determination of positions on linear axes, linear motors and movable units.
In these cases a particularly great measuring accuracy, extending into the nanometer range, is demanded in many areas.
Problems in detecting the results of measurements can be caused, for example, by swarf, fog from coolants, solvents, oil, grease, water and mechanical wear.
Linear measuring systems of the type mentioned at the outset are known, which were documented in a catalog xe2x80x9cMagnetisches Lxc3xa4ngenmess-System MS01-Technisches Handbuchxe2x80x9d [Manualxe2x80x94Magnetic Linear Measuring System MS01] by Noesis. The measuring system employed there includes a scale embedded in a groove, a connecting cable and an evaluation system composed of a sensor head and electronic evaluation device. The sensor head detects the position while being moved over the scale. In the process, the sensor detects information from magnetic fields and passes these signals on to the electronic evaluation device. The electronic evaluation device processes these signals into interface-usable protocols for the exact position determination.
A problem with known linear measuring system lies in that in case of repairs they cannot be exchanged if they are permanently integrated in the respectively existing component or in the machine. To protect the scales against swarf, fog from coolants, solvents, oil, grease, water and mechanical wear, they are integrated in closed spaces, which for disassembly, or reassembly, cannot be opened without damage, i.e. the parts surrounding the space, in particular along the measurement axis, of known linear measuring devices cannot be used again as a whole, or without reworking.
A linear measuring system is known from DE 199 39 659 A1, wherein the scale is embodied as a flexible component, which is surrounded by a flexible encapsulation which completely surrounds the scale.
A linear measuring system is described in the not pre-published WO 02/052220 A2, whose priorities are DE 100 64 734 and DE 201 10 905, wherein a conduit, which is only accessible from the front is provided, into which a measuring tape can be inserted and fixed in place.
Based on the mentioned prior art, an object of the present invention, or the technical problem on which it is based, is to disclose a position measuring system which, while maintaining a high degree of accuracy and dependability, assures efficient manufacture and simple exchange, wherein at the same time the processing outlay for producing the groove at the guide profile can be clearly reduced.
This object is attained by a support body designed in accordance with a support body that includes a groove with lateral wall areas cut into a support body and a profiled unit. The profiled unit including a profiled area attached to both a cover flange with a laterally protruding contact area and a scale, wherein the profiled area is inserted in a releasably fixable manner into the groove from an open side of the groove, and while the profiled area is inserted into the groove, alignment of the scale takes place by contact of the protruding contact area against the lateral wall areas at a top of the groove.
A position measuring system in accordance with the present invention is provided by a groove with lateral wall areas cut into a support body and a profiled unit. The profiled unit includes a profiled area attached to both a cover flange with a laterally protruding contact area and a scale, wherein the profiled area is inserted in a releasably fixable manner into the groove from an open side of the groove, and while the profiled area is inserted into the groove, alignment of the scale takes place by contact of the protruding contact area against the lateral wall areas at a top of the groove. The position measuring system further includes at least one sensor for scanning the scale.
A position measuring system in accordance with the present invention is also provided by a scale which is arranged in a groove provided on a profiled body. A profiled unit includes a hollow profiled area attached to a cover flange with a laterally protruding contact area, wherein the scale is releasably provided inside the hollow profiled area and the hollow profiled area is inserted into the groove from an open side of the groove in a manner where the scale is releasably fixed in place. With the profiled unit inserted into the groove, alignment of the scale takes place by contact of the protruding contact area against a lateral edge area on a top of the groove. At least one sensor which is moved along the scale and detects information stored on the scale and an evaluation unit that evaluates the information received from the at least one sensor.
The position measuring system of the present invention is advantageously distinguished in that a profiled unit is provided which, in cross section, has a hollow profiled area and a cover flange with two laterally protruding contact areas, wherein the scale is releasably provided within the hollow profiled area, the hollow profiled area can be releasably fixed in the groove from the open side of the latter and, when the profiled area has been inserted into the groove, the alignment of the scale takes place by the contact of the protruding contact areas of the profiled unit with the tops of the lateral edge areas of the groove.
This position measuring system is distinguished by an especially economical manufacture. The profiled unit can be separately produced. The scale can be inserted into the profiled unit in a simple way and, in case of repairs, pulled out of it again. A particularly large advantage lies in that the groove bottom in the guide profile need not be made with extremely high accuracy, since the alignment of the scale inside the groove takes place by the contact of the protruding contact areas of the cover flange with the top of the lateral edge area of the groove. These edge areas can be made with high accuracy at a substantially smaller cost in comparison with the groove bottom.
A particularly preferred embodiment is distinguished in that the hollow profiled area has a resilient wall which, with the profiled unit inserted into the groove, comes to rest in a fixing manner on undercut areas of the groove, in particular inclined surfaces of the latter.
In a particularly preferred embodiment variation, the wall of the hollow profiled area of the profiled unit is embodied in such a way that the profiled unit can be inserted into the groove by applying a vacuum to the interior of the hollow profiled area.
A particularly advantageous further development, which assures a simple and problem-free removal, is distinguished in that the wall of the hollow profiled area of the profiled unit is embodied in such a way that the profiled unit can be removed from the groove without problems when an overpressure is introduced into the hollow profiled area.
For assuring an exact positioning of the scale inside the groove, or inside the profiled unit in a simple way, a particularly preferred embodiment is distinguished in that, when the profiled unit has been inserted into the groove, the resilient wall of the hollow profiled area fixes the scale in place inside the hollow profiled area.
In accordance with an advantageous embodiment of the measuring system of the present invention it is also possible to releasably clip or snap the profiled unit into the groove from the direction of the open side of the latter.
Metallic materials or plastics, in particular extrudable plastics, are preferable choices for the profiled unit.
The measuring system in accordance with the present invention can be employed without any problems in a magnetic, inductive or optical measuring system.
Further embodiments and advantages of the present invention ensue by combining various elements described and claimed in the present application with each other in any desired way, as long as they do not obviously cancel each other.
The present invention, as well as advantageous embodiments and further developments thereof will be described in greater detail and explained in what follows by the examples represented in the drawings. The characteristics which can be taken from the specification and the drawings can be used in accordance with the present invention individually or together in any desired combination.
The idea on which the present invention is based will be described in greater detail by exemplary embodiments represented in the drawings.